Process for dyeing polypropylene and polyformaldehyde fibers containing zinc compounds with metallisable dyestuffs



United States Patent 3,186,788 PRQCESS FOR BYEBIG POLYPROPYLENE ANDPGLYFOlhl/IALDEHYDE FEEERS (ZONTAKNDJG Emil CUMPOUNDS WETHP/EETALLISABLE DYE- STlJe' s 8 Walter Percival Mills, Manchester,William Alexander QNeill, Harrogate, and Raymond Price, Manchester,England, assignors to imperial Chemical industries Limited, London,England, a'corporation of Great Britain No Drawing. Filed Nov. 19, 1962,Ser. No. 233,790 Claims priority, application Great Britain, Dec. 1,1161, 43,033/ 61 9 Claims. (Ci. 8-42) This invention relates to animproved dyeing process and more particularly to an improved process fordyeing polyolefine and polyacetal fibres which contain metal compounds.

it is known that polyolefine and polyacetal fibres containing metalcompounds may be dyed with metallisable dyestufis, and that by thismeans the dyestulf becomes firmly anchored within the fibre.

United States application Serial No. 174,255, filed February 19, 1962,describes a process for the production of coloured shaped articles ofpoly-ot-olefines, in particular coloured fibres of stereoregularpolypropyL ene, wherein there is incorporated a basic or anionicexchange substance which contains a metal, characterised in that thearticle is dyed with an acid dyestufi which forms a chelate compound.

United States application Serial No. 212,705, filed luly 26, 1962,describes a process for the production of coloured shaped articlescontaining or consisting of polyacctals, wherein there is incorporated abasic or anionic exchange substance which contains a metal,characterised in that the article is dyed with an acid dyestufi whichforms a chelate compound.

We have found that when poly-u-olefine or polyacetal fibres containingmetal compounds are dyed with metallisable dyestuffs the resultingdyeings have poor fastness to rubbing. Frequently also we have foundthat the dyebaths do not exhaust satisfactorily and the resultingdyeings have poor fastness to solvents. It appears that although much ofthe dyestufi becomes firmly anchored within the fibre, some metalcomplex formation takes place on the surface of the fibre yielding aloosely bound dyestufi metal complex which is easily removed by rubbingand in some cases by solvents. The present invention provides animproved process for dyeing the aforesaid fibres with metallisabledyestuffs and avoids the defects of the known process.

According to the invention we provide a process for the production ofcoloured polyolefine and polyacetal fibres containing compounds ofpolyvalent metals which comprises dyeing said fibres with a metallisabledyestulf which is devoid of sulphonic acid groups and treating saidfibre with an aqueous solution of a sequestering agent.

As examples of polyolefin and polyacetal fibres we mention polymers andco-polymers of ethylene and propylene, particularly stereoregularpolypropylene, and poly formaldehyde.

Examples of polyvalent metals which may be contained in the polyolefineor polyacetal fibres used in the process of the invention include zinc,copper, nickel, chromium, cobalt, magnesium, aluminium, calcium,titanium, zirconium, and rare-earth metals such as praseodymium, ceriumand lanthanum. The preferred metals are, however, nickel and especiallyzinc.

The metallisable dyestuffs which may be used in the process of ourinvention may be of any desired series, for example of theanthraquinone, azo, tormazan, aza- ICC methine or heterocyclic series.The dyestuffs may be devoid of substituents imparting water-solubility,that is to say they may be of the water-insoluble disperse type,

in which case they may be applied to the fibre by known techniques forthe application of disperse dyes to fibres. Alternatively the dyestuffsmay carry substituents imparting water-solubility (for examplecarboxylic acid groups or salts thereof, but not sulphonic acid groups)provided that a water-insoluble complex is formed between the dyestuffand the metal contained in the fibre, and in this case the dyestuffs areapplied to the fibre from aqueous solution.

Metallisable azo dyestuffs which may be used in the process of theinvention include dyestuffs containing hydroxy, alkoxy, carboxy,carbalkoxy or amino groups in ortho position to the azo linkage anddyestuffs in which a heterocyclic nitrogen atom adjacent to the azolinkage takes part in chelation. As specific examples of such dyestufiswe may mention o-hydroxyazo dyes such as: 2 hydroxy 5cyclohexylazobenzene, 2 hydroxy 4' dodecyl 5 methylazobenzene, 2 hydroxy4' nitro 5 methylazobenzene, 2'54 dichloro 2 hydroxy 5 methylbenzene, l(4 methylphenylazo)-2- naphthol.

o:o-Dihydroxyazo dyes such as: 2:2'-dihydroxy-5- chloro 5dodecylazobenzene, 2:2 dihydroxy 3 chloro 5 methylazobenzene, 2:2dihydroxy 4 (N ethyl N-dodecylamino)-5'-nitroazobenzene, 1-(5'- chloro2' hydroxyphenylazo)-2-naphthol, 1-(3-nitro- 2' hydroxyphenylazo) 2naphthol, 2 (5'- chloro 2' hydroxyphenylazo) 1 naphthol, 1 (4'dodecylphenyl) 3 methyl 4 (2" hydroxy 4" nitrophenylazo) 5 pyrazolone, 1phenyl 3 methyl droxy 2 carboxy 4 nitro 5 methylazobenzene,

1 (2 carboxyphenylazo) 2 naphthol, 1 phenyl 3 methyl 4 (2' carboxy 4'nitrophenylazo) S-pyrazolone.

o-Hydroxy-o'-alkoxyazo dye such as: 2 hydro 2 methoxy 4' (N:Ndibutylamino) 5 methylsulphonylazobenzene, 2 methoxy 5:5 dimethyl 2hydroxyazobenzene, 2 hydroxy 2 methoxy 5' methyl 5 dodecyl 4phenylazo-azobenzene, 2 hydroxy 2' methoxy 5:5 dimethyl -4' (2":5"dimethylphenylazo)azobenzene, 1 (2' methoxy -5' methylphenylazo)-2-naphthol.

.olydroxy-o aminoazo dyes such as: 1 (2 hydroxy- 4 nitrophenylazo) 2naphthylamino, 4 (2' hydroxy 5 sulphamylphenylazo) 5 amino l phenyl 3methylpyrazole, 8 (2' hydroxynaphthylazo) quinoline, 3 (2 hydroxy 5methylphenylazo)- quinoline, l (benzthiazol 2 ylazo) 2 naphthol, 1(thiazo 2 ylazo) 2:4 dihydroxy benzene, l (indazol- 7 ylazo) 2 naphthol,1 (1'22z3z4 tetrazol-S '-ylazo) -2-naphthol.

o-Hydroxy-o-acetylazo dyes such as: Z-hydroxy-S-methyl-2-acetylazobenzene.

In other azo dyes which may be used in the process of the invention theazo group does not form part of the metallisable system. As examples ofsuch dyestufls we may mention azo dyes from 8-hydroxy quinoline, suchas: 5 (4' dodecylphenylazo) 8 hydroxyquinoline, 5 (4 methylphenylazo) 8hydroxyquinoline, 5 (2' cyanophenylazo) 8 hydroxyquinoline, 5 (4cyclohexyloxycarbonlyphenylazo) 8 hydroxyquinoline, (2':4dichlorophenylazo) 8- hydroxyquinoline, 5 (4' nitrophenylazo) 8hydroxyquinoline, 5 (2 chloro 4' nitrophenylazo) 8 hydroxyquinoline, 5(2'24 dimethylphenylazo) 8 hydroxyquinoline, 5 (4' cyano 2'trifluoromethylphenylazo) 8 hydroxyquinoline, 4 dodecyl 4 (8"- hydroxy1"-quinol5"-ylazo) azobenzene, 4-( 8"-hydroxyl"-quinol-5"-ylazoazobenzene.

Azo dyes from 4-hydroxybenzthiazole, such as: 7 (2z4 dichlorophenylazo)4 hydroxybenzthiazole, 7- 2'-nitrophenylazo -4-hydroxybenztbiazole, 7-4-dodecylphenylazo)-4-hydroxybenzthiazole,7-(4-dodecyloxycarbonylphenylazo) 4 hydroxybenzthiazole,2:2:5'-trimethyl-5-methoxy-4 (4"-hydroxybenzthiazol-7"-ylazo)azobenzene.

Azo dyes from 4-hydroxyacridine, such as: 1-(2:4-dichlorophenylazo-4-hydroxyacridine.

Azo dyes from 4-hydroxybenzoxazolone, such as: 7-(4'-cyclohexyloxycarbonylphenylazo -4-hydroxybenzoxazole.

Azo dyes from 7-hydroxyindazole, such as:4-(4'-nitrophenylazo)-7-hydroxyindazole.

Azo dyes from salicylaldoxime, suchas:2-octyloxycarbonyl-3'-oximinomethyl-4-nitro-4'-hydroxyazobenzene, 3oximinomethyl 4 hydroxy 4 cyclohexyloxycarbonylazobenzene,3-oximinomethyl-4-hydroxy-4-dodecylazobenzene, 3-oximinomethyl 4hydroxy-2':4'-dichloro azobenzene, 3 oximinomethyl 4 hydroxy 4'nitro-2'- cyanoazobenzene.

Azo dyes from o-hydroxyacetophenone oxime, such as:. 3 oz oximinoethyl 4hydroxy 4' dodecylazobenzene,

4-nitro-3'-ix-oximinoethyl-4-hydroxyazobenzene.

Azo dyes from salicylic acid and its esters, such as: 3 carboxy 4hydroxy 4' cyclohexyloxycarbonylazo benzene,3-carboxy-4-hydroxy-4-nitroazobenzene,3-incthoxycarbonyl-4-hydroxy-2'-cyanoazobenzene,3-n-butyloxycarbonyl-4-hydroxy-2' 4'-dichloroazobenzene, 3-carboxy 4hydroxy 2' methoxy 5' methyl 4'-(2":5"- dimethylphenylazo -azobenzene.

Azo dyes from 2-hydroXy-3-naphthoic acid and its esters, such as:l-(4-dodecylphenylazo)-2-hydroXy-3- naphthoic acid, 1-(4-nitro 2'chlorophenylazo) 2-hydroxy-3-naphthoic acid,1-(4'-nitrophenylazo)-3-ethoxy carbonyl-Z-naphthol, l-(4' methyl 2'nitrophenylazo)- 3-0ctyloxycarbonyl-Z-naphthol.

Azo dyes from 2-amino-3-naphthoic acid, such as:1-(4-dodecylphenylazo)-2-amino-3-naphthoic acid.

Azo dyes from o-dihydroxy compounds, such as: 3 :4 dihydroxy 4'ethoxyazobenzene, 3:4 dihydroxy- 4'-dodecylazobenzene.

Metallisable azamethine dyestuffs which may be used in the process or"the invention include: 2-hydroxy-3z5- .dichlorophenylmethylene 2hydroxyphenylimine, 2-hydroxy 4 nitrophenylmethylene 2' hydroxy 5'nitrophenylimine, 2 hydroxy 4 nitrophenylmethylene 2'-hydroxyphenylimine, 2 hydroxyphenylmethylene 2'- hydroxyphenylimine.

Metallisable formazan dyestuffs which may be used in the process of theinvention include: 3-cyano-l:5-di (o-hydroxyphenyl formazan, 13-diphenyl-5-(o -carboxyphenyl) formazan, 3 methyl-l:S-di-(o-hydroxyphenyl) formazan, 3-hexyl-l :S-di (ohydroxyphenyl)formazan, 3-ethoxycarbonyl-1 S-dio-hydroxyphenyl)-formazan.

Metallisable anthraquinone and heterocyclic dyestutfs which may be usedin the process of the invention include: hydroxy compounds such asalizarin, anthrarufimchrysazin, quinizarin, l-hydroxyanthraquinone,Z-hydroxyanthraquinone, beta-nitro-alizarin, 5 6-dihydr0xy-7: 12-dioxonaphtho-[Zz 3-h] quinoline, 5:8 di(p-hydroxy-anilino)l:Z-dihydroxyanthraquinone, 1:4 di(beta-hydroxy ethylamino)-5 :8dihydroxyanthraquinone, 2:7-dibromo- 1:5 diamino 4: 8dihydroxyanthraquinone, and 3:6-dibromo-l 8-diamino-4S-dihydroxyanthraquinone.

sequestering agents which may be used in the process of the inventioninclude sorbitol, Water-soluble polyphosphates such as pyrophosphatesand triphosphates, oxalates, citrates, tartrates, gluconates andthioclycollates, also aminotriacetic acid,hydroxyethylalkylenediarninetriacetic acid,diethylenetriaminepentaacetic acid, and especially ethylenediaminetetraacetic acid, and their water-soluble salts.

In the process of the invention, treatment of the polyolefine orpolyacetal fibre with an aqueous solution of a sequestering agent maybecarried out before, during or after the treatment with a metallisabledyestuif.

If desired, the treatment with a sequestering agent may be carried outby incorporating a sequestering agent in a scouring bath such as iscommonly used for scouring polyolefine or polyacetal fibres prior todyeing. Dyeing of the fibre may then be carried out in:kn0wn manner.Alternatively the dyeing may be carried out from a dyebath which.contains a sequestering agent. Excellent results are obtained byincluding a sequestering agent both in a preliminary scouring bath andalso in the dyebath and this is the preferred mode of embodiment of theprocess of our invention. After-treatment of the dyed fibre with asequestering agent is also of value, and if desired such anafter-treatment may be employed when a sequestering agent is included ineither the scouring bath or the dyebath, or both these baths.

The weight of sequestering agent used in any individual bath may be, forexample from about 1% to about 10% of the weight of the fibre, and thetemperature at which the treatment with the sequestering agent iscarried out may be for example between 50 and 150 C.

After carrying out the process of the invention the fibre may be rinsedand dried in normal manner. The dyeings obtained have improved fastnessto rubbing and to solvents when compared with similar dyeings obtainedwithout the use of a sequestering agent.

The invention is illustrated but not limited by the following examplesin which the parts are by Weight.

Example 1'= This example illustrates the treatment of a metal-containingpolypropylene textile material with a sequestering agent before dyeing.

A scouring bath is prepared by adding 4 parts of sodium oleylp-anisidine sulphonate and 8 parts of ethylenediaminetetraacetic aciddisodium salt to 4000 parts of water. 100 parts of polypropylene textilematerial containing isotactic polypropylene and 5% zinc stearate areplaced in this bath and heated to 85 C. for 30 minutes. The scouredmaterial is rinsed thoroughly in water and dyed at C. for 60 minutes ina bath containing 2 parts of alizarine dispersed in 4000 parts of water.The dyed polypropylene textile material is then rinsed in water,irnmersed for 15 minutes in a warm aqueous solution of a syntheticdetergent, again rinsed in water and dried. The

polypropylene is dyed a bordeaux shade of very good 4-hydroxyazobenzene(yellow orange) or any of the dyestuffs previously named in thisspecification. In all cases dyeings of good rubbing fastness areobtained.

The polypropylene textile material containing 5% zinc stearate may bereplaced by (a) A polypropylene textile material containing 92%isotactic polypropylene and 8% of aluminium stearate. A red shade isobtained from alizarine, a brown from l:2:3-trihydroxyanthraquinone, anorange from 3-nitroalizarine, a red-violet from 5:8-d-ihydroxyalizarine,a yellow from 4-nitro-3-carboxy-4'-hydroxyazobenzene, a red from1-(5'-chloro-2'hydroxyphenylazo)-2-naphthol, an orange from5-(4'-chloro-2'-methylphenylazo)-8-hydroxyquinoline and an orange from5-(2':4-dichlorophenyl- I5-(2':4'-dimethylphenylazo)-8-hydroxyquinoline, a red from 5 (4 cyano 2'trifiuoromethylphenylazo) 8-v hydroxyquinoline, a red from5-(2:4-dimethylphenylazo)8-hydroxyquinoline, a brown fromS-(quinol-S-ylazo)-8-hydroxyquinoline, a blue from5:8-di-(n-butylamino)alizarine, a reddish brown from122:3-trihydroxyanthraquinone, and an orangefrom 3-nitroalizarine. Allthe dyeings have good rubbing fastness.

(c) A polypropylene textile material containing 97% isotacticpolypropylene and 3% chromium ol'eate. An orange shade is obtained from5(2':4-dichlorophenylazo)-8-hydroxyquinoline, a red from5(4-nitrophenylazo)-8-hydroxyquinoline, a blue from5:8-di-(n-butylamino)alizarine and a violet from 1:2:5:8-tetrahydroxyanthraquinone. All the dyeings have good rubbing fastness.

(d) A polypropylene textile material containing 95% of isotacticpolypropylene and 5% calcium oxide. A maroon shade is obtained fromalizarine and a brown from 5-(4'-nitrophenylazo)-8-hydroxyquinoline. Thedyeings have good rubbing fastness.

(e) A polypropylene textile material containing 95% of isotacticpolypropylene and 5% of magnesium stearate. A maroon shade is obtainedfrom alizarin and an orange from5-(2'z4'-dimethylphenylazo)-8-hydroxyquinoline. The dyeings have goodrubbing fastness.

Example 2 This example illustrates the use of a sequestering agentduring the dyeing of a metal-containing polypropylene textile material.

The zinc-containing polypropylene textile material used in Example 1 isscoured at 85 C. for 30 minutes in a 0.1% solution of sodium oleylp-anisidine sulphonate, rinsed and then dyed at 100 C. for 60 minutes ina bath containing 2 parts of alizarine dispersed in a solution of 2parts of ethylenediaminotetraacetic acid disodium salt in 4000 parts ofwater. The rubbing fastness of the dyed material is very good.

Dyeings of very good rubbing fastness are also obtained in this wayusing any of the metal-containing polypropylene textile materials ordyestuffs mentioned in Example 1.

Example 3 This example illustrates the use of a sequestering agent forafter-treating a dyed metal-containing polypropylene textile material.

100 parts of a polypropylene textile material containing 95% isotacticpolypropylene and 5% zinc stearate is scoured at 85 C. for 30 minutes ina 1% aqueous solution of sodium oleyl p anisidine sulphonate. Thescoured material is rinsed and dyed at 100 for 60 minutes in adispersion containing 2 parts of alizarine in 400 parts of water. Thedyed material is then rinsed and immersed for minutes at 85 C. in a 0.2%aqueous solution of ethylenediaminetetraacetic acid containing asynthetic detergent. The final treatment removes some loose zinc complexof the dyestulf from the surface of the fibre and the resultant dyeinghas better fastness to rubbing than a dyeing obtained similarly, butwith omission of the ethylenediaminetetraacetic acid from theafter-treating liquor.

In place of alizarine in this example there may be used 122:5 :8tetrahydroxyanthraquinone or 3 nitroalizarine. Dyeings of good rubbingfastness are obtained.

6 Example 4 This example illustrates the use of a sequestering agentbefore and during the dyeing of a metal-containing polyproylene textilematerial. The zinc-containing polypropylene textile material used inExample 1 is scoured as in Example 1 and then dyed at 100 C. for 60minutes in a bath containing 2 parts of alizarine dispersed in asolution of 2 parts of ethylenediaminetetraacetic acid disodium salt in4000 parts of Water. The rubbing fastness of the dyed materialisexcellent.

In a similar way the other metal-containing polypropylene textilematerials described in Example 1 may be dyed with alizarine,2':4'-dichloro-2-hydroxy-S-methylazobenzene (yellow),l-(3-chloro-2'-hydroxyphenylazo)- Z-naphthol (red),1-(5'-chloro-2'-hydroxyphenylazo)-2- naphthol (red) or any of thedyestuffs of Example 1. The rubbing fastness of the dyeings is betterthan that of the dyeings obtained by the procedures described inExamples 1 and 2.

Example 5 This example illustrates the use of a sequestering agentbefore and after the dyeing of a metal-containing polypropylene textilematerial. I

The same polypropylene textile material as used in Example 1 is scouredand dyed as in Example 1 using 1 phenyl 3 ethoxycarbonyl 4-(2hydroxyphenylazo)-5-pyrazolone in place of alizarine. The modifiedpolypropylene material is then rinsed in water, immersed for 15 minutesat C. in a solution of 4 parts of sodium oleyl p-anisidine sulphonateand 8 parts of ethylene diamine tetraacetic and disodium salt in 4000parts of water, again rinsed with Water and dried. The polypropylene isdyed a yellow shade of good rubbing fastness. In this example sodiumoleyl p-anisidine sulphonate may be replaced by anonylphenolethyleneoxide condensate. The rubbing fastness is again verygood.

In place of1-phenyl-3-ethoxycarbonyl-4-(2'-hydroxyphenylazo)-5-pyrazolone there maybe used 1-(2-carboxyphenylazo)-2-naphthol (red), 1-phenyl-3-methyl-4-(2' carboxyphenylazo) 5 pyrazolone (red), 8 (2'-hydroxynaphthylazo)-quinoline (red), or 1-(2-methoxyphenylazo)-2-naphtl1ol(pink). The dyeings obtained as described in this example are of betterrubbing fastness than dyeings obtained by the procedure of Example 1 butnot quite so good as those obtained by the procedure of Example 4.

Example 6 This illustrates the use of a sequestering agent, beforeduring and after the dyeing of a metal-containing polypropylene textilematerial. The same polypropylene textile material as used in Example 1is scoured as in Example 1 and then dyed at C. for 60 minutes in a bathcontaining 2 parts of 5-(4'-nitrophenylazo)-8-hydroxyquinoline dispersedin a solution of 2 parts of ethylenediaminetetraacetic acid disodiumsalt in 4000 parts of water. The dyed polypropylene textile material isthen rinsed in water, immersed for 15 minutes at 85 C. in a solution of4 parts of sodium oleyl-o-anisidine sulphonate and 8 parts ofethylenediaminetetraacetic acid disodium salt in 4000 parts of water,again rinsed with Water and dried. The polypropylene is dyed a brownshade of excellent rubbing fastness. In this example sodiumoleyl-p-anisidine maybe replaced by a nonylphenol ethylene oxidecondensate. The rubbing fastness is again excellent.

In place of 5-(4'-nitrophenylazo)-8-hydroxyquinoline in this examplethere may be used 5-(2'-chloro-4'nitrophenylazo)-8-hydroxyquinoline(brown), 5-(2' :4'-dimethylphenylazo)-8-hydroxyquinoline (orange),5-(4'-cyano 2' trifiuoromethylphenylazo) 8 hydroxyquinoline (orange), 5(quinol-8'-ylazo) 8 hydroxyquinoline (bown),7-(2':4'-dichloro-phenylazo) 2 acetylaminolhydroxybenzthiazole (yellow),7-(4'-nitrophenylazo) 4- hydroxybenzthiazole (orange) or1-(4'-diethylaminophenylazo)-4-hydroxyacridine (brown).

The dyeings all have excellent fastness to rubbing.

Example 7 Example 8 Example 1 is repeated using as the textile material,in place of the zinc modified polypropylene, 100 parts of a polyacetaltextile material containing 95% of polyforrnaldehyde copolymer and ofzinc nonanoate. The modified polyacetal is dyed a bordeaux shade ofexcellent rubbing fastness.

In all the above examples ethylenediaminetetraacetic acid may bereplaced by sodium pyrophosphate, sodium hexametaphosphate, oraminotriacetic acid. Dyeings of very good rubbing fastness are obtained,though the results are a little interior to those obtained withethylenediaminetetraacetic acid.

We claim:

1. A process for the production of coloured textile fibres selected fromthe class consisting of stereoregular polypropylene and polyformaldehydefibres containing a zinc compound which comprises dyeing said fibreWitha metallisable dyestutf which is devoid of sulphonic acid groupswhile yielding a water-insoluble zinc complex and treating said fibrewith an aqueous solution of a sequestering agent selected from the classconsisting of watersoluble pyrophosphates, hexametaphosphates,aminotriacetates and ethylenediaminetetraacetates.

2. A process for the production of coloured stereoregular polypropylenefibre containing a zinc compound which comprises dyeing said fibre witha metallisable dyestufi" which is devoid of sulphonic acid groups whileyielding a water-insoluble zinc complex and treating said fibre with anaqueous solution of a water-soluble ethylenediaminetetraacetate.

3. A process according to claim 1 wherein the fibres comprisestereoregular polypropylene,.the zinc compound is zinc stearate, thedyestuif is selected from the group consisting of anthraquinone, azo,formazan, .azamethine and heterocyclic metallizable dyestuffs yielding awaterinsoluble zinc complex and the sequestering agent is the sodiumsalt of ethylenediamine tetraacetic acid.

4. A process according to claim 1 wherein said metal compound is zincstearate and said sequestering agent is a water-soluble ethylenediaminetetraacetate.

5. A process according to claim 3 wherein the Weight of sequesteringagent utilized is from about 1 to about 10% of the weight of fibres andthe temperature of said treatment is between C. and C.

6. A process according to claim 1 wherein the treat- 20 ment withsequestering agent is carried out before dyeing.

7. A process according to claim 1 wherein the treatment withsequestering agent is carried out during dyeing.

8. A process according to claim 1 wherein the treatment withsequestering agent is carried out after dyeing.

9. The product obtained by the process of claim 1.

References Cited by the Examiner UNITED STATES PATENTS 2,984,634 5/61Caldwell et al. 8 3,061,397 10/62 Streck 842 3,071,428 1/63 Gross et a18-42 OTHER REFERENCES Millson: American Dyestuff Reporter, Jan. 30,1956, pp. P66-P81.

NORMAN G. TORCHIN, Primary Examiner.

1. A PROCESS FOR THE PRODUCTION OF COLOURED TEXTILE FIBRES SELECTED FROMTHE CLASS CONSISTING OF STEREOREGULAR POLYPROPYLENE AND POLYFORMALDEHYDEFIBRES CONTAINING A ZINC COMPOUND WHICH COMPRISES DYEING SAID FIBRE WITHA METALLISABLE DYESTUFF WHICH IS DEVOID OF SULPHONIC ACID GROUPS WHILEYIELDING A WATER-INSOLUBLE ZINC COMPLEX AND TREATING SAID FIBRE WITH ANAQUEOUS SOLUTION OF A SEQUESTERING AGENT SELECTED FROM THE CLASSCONSISTING OF WATERSOLUBLE PYROPHOSPHATES, HEXAMETAPHOSPHATES,AMINOTRIACETATES AND ETHYLENEDIAMINETETRAACETATES.